How is psoriasis hereditary transmitted?
If both parents have psoriasis then the risk of children developing psoriasis is 75% and if one parent has psoriasis, the risk of children developing the disease is 15%.
Therefore, if you have psoriasis, your children will not necessarily also develop psoriasis. However, if a brother or sister (but neither parent) has psoriasis then the risk of other siblings developing psoriasis is 20%.
Will my first child be at risk?
Again, nothing is certain, so therefore information can only provide risk statistics, this does not mean any child with a predisposition to the condition with get it. There is to-date no evidence to suggest that first borne are more at risk than following children. It could just be down to circumstances leading to trigger factors.
What if I have another child, would they get it too?
If you already have one child with the condition, it is believed that your following child would have a 20% risk of developing this too, but that does not mean they will get the condition –this is just a risk factor.
What about twins?
There is a relatively low chance of identical twins both having psoriasis and the large number of chromosomes linked to psoriasis, suggests that it requires more than having the gene to develop the skin lesions.
It is thought therefore that psoriasis is a complex disease where the skin changes only occur in individuals who not only have a genetic predisposition for the condition but who have also encountered an environmental trigger such as infection and stress.
Unfortunately there is no sure way to confirm the exact triggers that caused the reaction to happen in your child. They could have experienced a certain situation(s), which could have caused the psoriasis to trigger. Such an experience could have been a traumatic one, or even a recent illness, such as a throat infection, especially one caused by streptroccal, or ear/chest infections.
Researchers further suggest that after such triggers flare-up the psoriasis, it is more likely to appear on skin sites that have been previously injured. This could just be a small patch, or a patches, not necessarily all over the body, which is extremely rare indeed.
It is likely that what is currently called psoriasis may ultimately turn out to be a spectrum of clinically similar, but genetically different diseases.